fix content_statistics bug for VL, as one item can be assigned multiple projects in VL (use union instead of sum)
fix content_statistics bug for VL, as one item can be assigned multiple projects in VL (use union instead of sum)

aina1205/virtualliverf1,aina1205/virtualliverf1,aina1205/virtualliverf1,aina1205/virtualliverf1